Yeah. It's a cave spider dressed in a diamond block.
Note: Minify the command to avoid issues :)
SICKNESS POTION (4 TROLLING)
Wear TheDiamondMinecart's Head!!!!
MINDBLOWER Chest
LUCKY WORLD!!!!!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)